Device for tensioning and binding bands on boxes, bales, and the like



Dec. 14 1926. 1,610,858-

5. HOFFMANN v DEVICE FOR TENSIONING AND BINDING BANDS ON BOXES, BALES,AND THE LIKE Filed July 15,1925

izue'zzior.

Qnzz

Patented Dec. 14, 1926.

UNITED STATES I 1,610,85t PATENT OFFICE.

EM IL HOFFMANN, 0F COLOGNE, GERMANY.

DEVICE FOR TENSIONING AND BINDING BANDS 0N BOXES, BALE S, AND THE LIKE.

Application filed July .18, 1925, Serial No. 43,359, and in Germany July15, 1924.

This invention relates to devices for tensioning bands of hoop iron andthe like around boxes or bales and then binding together the ends of thetensioned .band.

Devices of this general character are known for binding wires .on boxesand in such devices gripping jaws are carried by levers and moved bymeans of a screw cam for the purpose of applying the tension. The camsare mounted loosely on their shaft and are returned to their initialposition by a spring after each operation of tensioning the wires iscompleted. Forthe purpose of applying the tension the levers carryingthe gripping jaws are moved apart in opposite directions by the rotationof the cams.

This known form of tensioning device is not suited for stretching andbinding flat bands, as the grippers, when applying the tension, move inthe arc of a circle and it is thus impossible to guide the ends into aclip sleeve, which is used in the known manner for binding the ends ofthe hoop iron. The return of the tensio'ning cams by means of springs isalso objectionable as I the grippers are thereby held up by the cam andfailure of the machine to operate properly may result from the improperreturn i of the grippers. Finally the known device mentioned is notadapted for use with boxes or bales requiring widely different degreesof tension and the range of usefulness of any given machine wastherefore strictly limited. f

According to this invention these defects are removed; In the firstplace the gripper jaws, according to this invention, are carried byslides mpvable in a straight line parallel to'the axis of the rotatableshaft or spindle on which the screw cams are rigidly mounted. In thisway the ends of the bands duringtensioning are properly entered in-thebindingsleeve and are in exact register, so that reliable binding of theband can be effected. The screw cams terminate in a peak at theirhighest point, which is the point located nearest to the gripper slides,and from this peak the cam suddenly recedes. per slides thus rise on thescrew part 0 the cam to apply the tension. until the rollers reach thepeak, whereupon the gripper slides are quickly returned to their initialposition The cam rollers carried by the grip-.

shaft. 0, the slides are first caused to apis .thus renderedunnecessary. The hand lever which effects the rotation of the spindleand that which effects the operation of the punch of the binding deviceare so located that they act mutually as steadying handles, and therebyrender the entire machine more convenient and serviceable. The returnmovement of the gripper slides under the action of their springs may beadjusted by means of stop pins and the degree of tension applied onrotation of the tensioning cams thereby altered as required.

Referring to the accompanying drawings:

Figure 1 is :a front elevation of a band tensioning machine made withthis invention.

Figure 2 is a plan of the same.

Figure 3 is a front elevation showing the position of' the gripperslides after the bands have been tensioned and the binding sleeve is inposition to be operated on bythe punching device so as to clamp orbindthe ends of the bands together.

. Figure 4 is a. cross section at right anglesto Fig. 3. i In carryingthe invention into efi'ect, a

hollow shaft or spindle 0 is supported rotatablv in bearings 6 formed inupstanding brackets cast on the bed a or fixed thereto in any suitablemanner. On the shaft 0, there are rigidly fixed two cams d, which, onthe side facing the centre of themachine, have spiral or screw formedworking faces. At the point nearestto the centre of the ma chine onthese cam faces, the screw face terminates in a peak, d after which, inthe direction of rotation of the shaft 0, there is a drop in the cam inthe form of a substantially axial portion 05 The gripper slides f aresuitably guided to slide along the shaft 0 parallel to the axis of theshaft and in a straight line. These slides carry arms on the screwshaped face of the tensioning cams (Z. Wedge shaped gripping jaws g,

operated by a hand lever h. are provided to grip the fastening band B inthe known manner. There are two such slides and two cams, so arrangedthat on rotation of the proach to the centre of the machine, that is tomove from the position shown in Figure 2 to that shown in Figure 3. Indoing so, the band B, which has its ends clamped in the gripper. jaws gis tensioned.

The rotation of the shaft 0 is effected by bands, the binding operationbeing effected means of a ratchet lever It having a pawl Z pivoted to itand engaging in a ratchet vwheel i keyed to the hollowshaft 0. The

tensioned band B has its ends entered in a flattened sleeve H which hasbeen inserted by indenting or suitably punching the sleeve so that iteffectively holds and retains the band B in the tensioned state.Thestalnp- -ing device 0 is located about the centre of the machine andcomprises a slidable punch n centrally mounted in a suitableupstandingbracket on the machine bed an and two side clamps m also slidable inthe" said bracket 0 and adapted to clamp the sleeve H during thetensioning operation and also during the punching of the sleeve by thepunch a. For this purpose, a pivoted lever 0. suitably mounted on thebracket 0 has on its boss three cam parts, two similar side parts 0which operate the clamps m, and a central cam part 0 which operates thecen-. tral punch a. As can beseenin Figure 4, the lever 0 is turnedcounter clockwise-to theleftto clamp the sleeve, and in this positionacts as asteady to hold the bed a during the operation of tensioning andthe hand lever is in a similar way performs the same function during theoperation of punching. I

Inside the hollow shaft 0 there is provided a spiral spring p which isfixed at its ends to cross bars 3, which pass radially through sideslots '1" in the shaft 0 and have smallrollers s at their ends whichcontact with the gripper slides 7 so as to press these slides apart andthereby cause the rollers f to follow the contour of the' screw shapedfaces of the cams (5. When the shaft 0 is rotated so that the top halfis coming towards the observer in Figure 1, the spring 71 is compresseduntil the peak of the cams is reached. In this position the punchingoperation is performed on the sleeve H. Immediately the peak of the camshas been passed, the slides are free to be moved back into their initialpositions by the direct action of the springs p, without requiring thecam to be given a rotation in the reverse direction.

The distance which the gripper slides spring back under the action ofthe spring mechanism described, may be regulated in 'anv'suitablemanner, so as to vary as required the degree of tension imparted to theband B. In the form shown, this regula tion is effected by means ofstops, which may be in the form of pins adapted to be inserted in one orother of the holes\t in 1,610,858 v c I times,.gripper slides mounted toslide on,

saidshaft and adapted to be moved axially by said tensioning cams,resilient means adapted to maintain said gripper slides in operativecontact with said tensioning cams, and means located on said bed platebetween saidgripper slides for binding the tensioned and.

2. A device for tensioning and binding bands of hoop iron or the likearound boxes,

bales or the like having incombination, a

bed plate, a rotatable shaft mounted on-said bed plate, gripper slidesfor gripping the ends of and tensioning a band, said slidesbeing,movable in straight lines parallel to F the axis of the shaft,screw shaped tension: ing cams mounted to rotate with said shaftandadapted to operate said slides, said cams having each a peak, whichbecomes operative when the slides have tensioned the band,

and a sudden drop portion'which immediately follows the peak, springmeans operable on said gripper slides to cause the same to follow thecontour of the screw cam and llg ealis for'binding the ends of thetensioned an I,

3. A device for tensioning and binding bands of hoop iron or the likearound boxes, bales or the like having in combination a bed plate, arotatable shaft mounted on said bed plate, said shaftbeing hollow andhaving radial .slots extending axially therein, gripper slides forgripping the ends of and tensioning a band, said slides being guided onsaid shaft, tensioning cams mounted to rotate with saidshaft andiadaptedto operate said slides in thedirection to tension the band, a spiralspring within the said hollow shaft, vcross pins on the ends of saidspring and projecting radially throughzthe' tion to that required fortensioning the band and means located on the. bed plate between x thegripper slides for binding the ends of the tensioned 'band.

4c; A device for tensioning and binding bands ofhoop iron or the likearound boxes, bales or the like having in combinat1on, a bed plate, arotatable shaft mounted on said bed' plate, [gripper slides forgrlppingthe ends of and tensioning a band, said slides being guided on:said shaft toslide axlally on said shaft, tensioningeams mounted rigidlyon said shaft to rotate therewith and adapted to move said gripper.slides towards one another to tension the band, aratchet lever foroperating said shaft, means located on said bed plate between thegrippers 'for binding the ends of the tensioned band and a hand leverfor operating said means, said recited hand levers being arranged to actmutually as steadying levers during the operation of one or other ofsaid levers.

5. A devicefor tensioning and binding bands of hoop iron or the likearound boxes,

bales or the like having in combinaton, a bed plate, a rotatable shaftmounted on said bed plate, gripper slides for gripping the ends of andtensioning a band, said slides being movable in straight lines parallelto the axis of the shaittensioning cams mounted rigidly on said shaft torotate therewith and adapted to move said gripper slides towards oneanother to tension the band, means for adjusting the sliding movement ofsaid slides and means located on the bed plate between said gripperslides for binding the ends of the tensioned band.

' EMIL HOFFMANN.

